JP2015525664A - Spring loaded injection device with injection button - Google Patents

Abstract

The present invention relates to a spring-loaded medical injection device having an injection button (10) for automatically discharging a set dose of medicine. The injection device was distorted to discharge a set dose, and a housing having a dose setting member (20) for distorting the injection spring when setting the dose size to be injected A release element (30) for releasing the injection spring is provided. The injection button (10) can move in the distal direction against the bias of the return spring (1), and can move in the proximal direction by the force of the return spring (1). Furthermore, the injection button (10) moves with the release element from the first position to the second position. The release element (30) is further connected to the injection button (10) by a plurality of fingers (31, 15), the plurality of fingers (31, 15) being connected to the release button (10) in the first position by the injection button (10). 30) in the first position so that the axial distance can be moved independently of the 30) and in the second position both the injection button (10) and the release element (30) can be moved axially. The injection button (10) is disengaged from the release element (30) and the injection button (10) is engaged with the release element (30) in the second position. [Selection] Figure 5

Description

  The present invention relates to a release mechanism for an automatic spring driven injection device. The present invention relates in particular to the connection of an injection button to a release element, and more particularly to a mechanism for causing the injection button to engage and disengage the release element depending on its axial position.

  An automatic spring driven injection device is disclosed in International Application No. 2006/076921. FIG. 10 shows an embodiment in which a tubular release member is coupled to a proximally located injection button, where the user can place the injection button with a fingertip of a return spring contained between the housing and the injection button. It can be pushed distally against the bias. A rotary dose setting button for setting the dispensed dose size is connected to the housing. When setting the dosage size, the user further twists the injection spring. The set dose can be dispensed by the action of a proximally located injection button. When the user pushes the injection button in the distal direction, the distal end of the release tube engages with the housing to free the injection spring and drive the piston rod forward, thereby dispensing the set dose. The drive member is moved so as to release When the user lifts the finger away from the injection button, a return spring contained between the housing and the injection button raises the injection button and the release tube proximally so that the drive member re-engages the housing; The injection spring is prevented from discharging further medicament from the cartridge.

  An injection button of a manual injection device is described in EP 594,357. The injection button has a plurality of elastic legs integrally molded with the rest of the injection button so that when the user lifts his finger from the injection button, the injection button is lifted back to the initial position.

  In addition, US Pat. No. 5,928,202 discloses a coupling system for a push rod and piston in a medical syringe. In this system, when a plurality of elastic fingers are moved into the channel, the elastic fingers are deflected inward.

  International Application No. 2007/071080 and International Application No. 2008/031235 show a solution similar to the disclosure of International Application No. 2006/076921, where the return spring is the injection button when the user removes the finger from the injection button. To the proximal direction.

  In the embodiment shown in FIG. 10 of International Application No. 2006/076921, it is important that when the user removes the finger from the injection button, the drive member quickly re-engages with the housing to prevent further injection.

  However, there is usually a tolerance in the connection between the injection button and the release tube. In addition, tolerances can exist in the spring. As a result of these tolerances, when the return spring is most compressed (ie during injection) and the user lifts his finger from the injection button, the initial force of the spring is first used to lift the injection button and then the injection button is in the series. Is used to engage and lift the release tube at the end of its tolerance, thereby re-engaging the drive. As a result, and depending on tolerances, only a limited spring force is available to lift the release tube, and it is the release tube lift that re-engages the drive member with the housing to prevent further discharge. That is the main drawback. It is very important that the re-engagement is done quickly and accurately as soon as the user removes the finger from the injection button, for example in order to properly interrupt the injection.

  It is an object of the present invention to provide a spring driven injection device for multiple automatic injections of a set dose, so that proper reengagement of the drive member is ensured independent of tolerances. The spring force that returns the button and release element is distributed, thereby making it possible to use a return spring, for example a polymer spring without pretension.

  The invention is defined in claim 1.

Thus, according to one aspect of the present invention there is provided an injection device for spring-driven injection of a liquid medicament, the injection device comprising:
A housing that constitutes the outer shell. The housing typically holds a cartridge that contains the drug, as well as the mechanical components that make up the dose setting mechanism and the injection mechanism.
A dose setting member connected to the housing, by which the user can distort the injection spring, the injection spring may be a torsion spring, and the torque can be applied without axial compression or very Dose setting member that accumulates with only limited axial compression.
An injection button, which can be performed by actuation of the injection button, usually by the user applying axial pressure to the button during injection, and in the absence of applied pressure, a return spring Is an injection button that returns the injection button to its initial position.

  In addition, a release element is provided that is operable between a first position and a second position.

  The release element is releasably connected to the injection button via a plurality of radially acting fingers. The fingers are provided integral with the release element or integral with the injection button.

  In the first position, the finger is in the disengaged position and the dose setting button is disengaged from the release element. Therefore, the dose setting button can move the axial distance independently of the release element.

  In the second position, the finger is moved to an engaged position that couples the injection button to the release member. The second position is preferably the position where the return spring prompts both the dose setting button and the release element in the proximal direction.

  The release element is an element in a mechanical configuration that releases the injection spring directly or indirectly to perform an injection, for example as shown in International Application No. 2006/076921, which application is by reference. Incorporated in this application.

  The release element does not necessarily have to be directly connected to the injection spring, but may be connected to the injection spring via a mechanism that releases the injection spring when the release element is activated.

  One feature of the present invention is that the injection button can move an axial distance independently of the release element in the first position, and in the second position, both the injection button and the release element are It can move in the axial direction.

  In this manner, the maximum force of the return spring when it is most compressed is first used to re-engage the release mechanism, after which the smaller portion of the spring force is when the return spring is in its most extended state. As it approaches, it is guaranteed to be used only to lift the injection button, independent of the release mechanism. In this manner, maximum force is available to re-engage the release element with the housing when stopping or interrupting the injection.

  A portion of the release element and a portion of the injection button are guided in a channel having a fixed diameter. The channel is preferably provided on either the dose setting member or the housing.

  One of the two elements, the release element or the injection button, comprises a plurality of fingers. The outer diameter formed by the outer edges of these fingers is preferably larger than the diameter of the channels so that as the fingers move axially within the channels, they are compressed radially.

  This radial movement of the fingers defines a boundary between the first position and the second position. In the first position, where the finger is outside the channel, the finger is in the disengaged position, while the release element is in its second position when the finger is squeezed in the channel.

  Thus, in the second position, the release element and the injection button are firmly connected and move axially together, while in the first position, the two elements are disconnected.

  The finger preferably comprises an inwardly projecting means that engages at the rear of the ridge provided on the injection button, thereby engaging the injection button in the second position, but the finger is provided on the injection button. If so, a ridge or track may be provided on the release element itself.

  The return spring is usually preferably not pre-distorted, but is not limited to this and is made of a suitable polymer material and as an integral part of the injection button or dose setting member (or alternatively as part of the housing) ) Can be molded. Alternatively, however, a normal metal compression spring can be used.

  Furthermore, according to the invention, the initial movement of the return spring when the injection button is released is transmitted directly to lift the release element, so that the return spring does not have to physically contact the injection button. Please keep in mind.

Definition:
An “injection pen” is typically an injection device having a longitudinal or elongated shape, such as a writing pen. Such pens typically have a tubular cross-section, and they can easily have a different cross-section such as a triangle, rectangle or square, or any variation of these shapes.

  As used herein, the term “drug” can be passed through a delivery means such as a hollow needle cannula in a controlled manner, such as any liquid, solution, gel or fine suspension. Of drug-containing flowable drugs. Exemplary agents include peptides, proteins (eg, insulin, insulin analogs, and C-peptides), and hormones, biologically derived or biologically active chemicals, hormonal agents, and gene-based chemistry. Includes drugs such as substances, nutritional formulas, and other substances that take both solid (dispensed) or liquid forms.

  “Cartridge” is a term used to describe a container containing a drug. The cartridge is typically made of glass, but can be molded from any suitable polymer. The cartridge or ampoule is preferably sealed at one end by a pierceable membrane called “septum”, which is pierced by the non-patient end of the needle cannula, for example. The opposite end is generally closed by a plunger or piston made from rubber or a suitable polymer compound. The plunger or piston is slidably moved inside the cartridge. The space between the pierceable membrane and the movable plunger holds the drug that is pushed out by the plunger reducing the volume of the space holding the drug. However, any type of container, whether rigid or flexible, can be used to contain the drug.

  The use of the term “automatic” in conjunction with an injection device means that the user of the injection device can perform the injection without delivering the force necessary to dispense the medicament. The force is typically transmitted by an electric motor or by a spring as described herein, which is usually distorted by the user during dose setting. Such springs are usually pre-distorted with a certain force to avoid the problem of delivering very small doses. Alternatively, the spring can be preloaded by the manufacturer with a preload sufficient to empty the drug cartridge through some number of doses. Typically, when performing an injection, the user activates a latch or button on the injection device to release the force accumulated in the spring.

All references cited herein, including publications, patent applications, and patents, are hereby indicated in their entirety as well as each reference is incorporated individually and specifically by reference. Are incorporated by reference to the same extent as if they were described in their entirety.
All headings and subtitles are used herein for convenience only and should not be construed as limiting the invention in any way.
The use of any and all embodiments, or the use of the exemplary language provided herein (eg, “etc.”) is intended only to facilitate understanding of the invention, and Unless otherwise stated, no limitation is imposed on the scope of the invention. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
The citation and combination of patent documents in this document are for convenience only and do not reflect any view of the validity, patentability, and / or enforceability of such patent documents.
This invention is intended to cover all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law.

  The invention will be described more fully in connection with the preferred embodiments with reference to the following drawings, in which:

FIG. 3 shows a cross-sectional view of a release mechanism where no pressure is applied. FIG. 6 shows a cross-sectional view of the release mechanism at the start of injection. FIG. 6 shows a cross-sectional view of the release mechanism when the release tube is engaged with the dose setting button. Figure 7 shows a cross-sectional view of the release mechanism with the injection button fully depressed. An exploded view of the release mechanism is shown. Figure 4 shows a cross-sectional view of a different embodiment.

  The drawings are simplified and simplified for clarity, and they show only those details that are essential to an understanding of the invention, and other details are omitted. Throughout, the same reference numerals are used for identical or corresponding parts.

  In the following, the terms “top” and “bottom”, “right” and “left”, “horizontal” and “vertical”, “clockwise” and “counterclockwise” or similar related expressions are used. , They refer only to the attached drawings, and do not refer to actual usage. The drawings shown are schematic representations, so the various structural configurations and their relative dimensions are intended for illustrative purposes only.

  In that context, as shown in FIG. 1, the term “distal end” in the accompanying drawings is usually intended to represent the end of an injection device carrying a needle, whereas the “proximal end” It may be convenient to define the term as intended to represent the opposite end carrying the injection button facing away from the needle.

  1-6 disclose a release mechanism of an automatic spring driven injection device.

  The embodiment shown in FIGS. 1-5 shows a release mechanism. An injection button 10 is provided at the proximal end of the injection device. Similar to that shown in FIG. 10 of International Application No. 2006/076921, the injection button 10 is guided axially by a dose setting button 20 rotatably connected to the housing.

  The release tube 30 is located in the center of the injection device. The release tube 30 operates at its distal end a mechanism for releasing the injection spring in order to discharge a set dose through the drive. An example of such a mechanism is disclosed in FIG. 10 of International Application No. 2006/076921.

  The return spring 1 is included between the dose setting button 10 and the injection button 20 and urges the injection button 10 in the proximal direction. The return spring 1 is preferably molded from a polymer material.

  In the first embodiment (FIGS. 1-5), the injection button 10 has a centrally located protrusion 11 with a radial ridge 12 at its distal end.

  The release tube 30 includes a plurality of fingers 31. In practice, only one of these fingers 31 needs to be flexible, and the other fingers 31 may be formed as a rigid support structure. These fingers 31 extend through a channel 21 provided in the dose setting button 20. However, the channel 21 may alternatively be provided in the housing or at any other suitable location. The finger 31 is proximally provided with an outwardly projecting extension that defines an outer edge 32 having a diameter greater than the inner diameter of the channel 21 defined by the wall 22.

  As shown in FIG. 2, during injection, when the user applies axial pressure (P) to the injection button 10, the injection button 10 is first moved distally until it engages the proximal end 33 of the release tube 30. Moving. Thereafter, as shown in FIG. 3, the release tube 30 moves with the injection button 10 in the distal direction.

  As the release tube 30 moves distally, the outer edge 32 of the finger 31 abuts the inner wall 22 of the channel 21 so that the finger 31 is deflected inward as shown in FIG.

  Internally, the release tube 30 includes a number of radially inwardly projecting knobs 34, the knobs of the injection button 10 as the projection 11 and the release tube 30 move distally into the channel 21. Engage with the protrusion 11 proximal to the radial ridge 12.

  When the user lifts the finger away from the injection button 10 so that no pressure is applied, the return spring 1 begins to lift the injection button 10 as shown by the arrow L in FIG. Since the injection button 10 in this position is locked to the release tube 30 by engagement between the ridge 12 and the knob 34, the maximum force of the return spring 1 when it is most compressed is It is transmitted to the release tube 30 so as to ensure re-engagement with the housing.

  When the release mechanism is released, the outer edge 32 has reached the position above the opening of the channel 21 (as shown in FIG. 3) and the remaining force of the return spring 1 is injected independently of the release tube 30. Used to move the button 10 until it reaches its initial position.

  In the last part of this scheme, even if the final force of the return spring 1 is insufficient to lift the injection button 10, it does not affect the release mechanism because the release tube 30 has already been lifted.

  The embodiment shown in FIG. 6 operates basically in the same manner as the first embodiment. Here, the injection button 10 further comprises a plurality of flexible arms 15 that function like the fingers 31 in the previous embodiment. The arm 15 has an outer edge 16 that defines a diameter that is larger than the inner diameter of the channel 21 such that the arm 15 is deflected inward when the outer edge 16 of the arm 15 contacts the inner wall 22 of the channel 21. When pushed inward, the inner protrusions 17 of these arms 15 engage at the rear of the ridge or track 35 in the release tube 30.

  When the return spring 1 is released, the spring force first moves the injection button 10 in the proximal direction with the release tube 30 until the drive member re-engages the housing, after which the residual spring force is applied to the injection button 10. Is used only to move the to its initial position.

  In FIG. 6, the return spring 1 is shown as a molded polymer spring element, but it can of course also be a normal metal compression spring. According to the present invention, the initial movement of the return spring 1 when the injection button 10 is released is transmitted directly to lift the release element 30, so that the return spring 1 need not physically contact the injection button 10. Note that there is no.

  In addition, as shown in FIG. 6, the dose setting button 20 includes an internal track 23 that engages a similar ridge (not shown) in the housing to rotatably connect the dose setting member 20 to the housing. Is provided.

  While several preferred embodiments have been shown above, the invention is not so limited and may be embodied in other ways within the scope of the subject matter defined in the following claims. That should be emphasized.

Claims (10)

A set dose amount having an injection button (10) which is movable in the distal direction against the bias of the return spring (1) and which is movable in the proximal direction by the force of the return spring (1); A spring-loaded medical injection device for automatically discharging a medicine, the spring-loaded medical injection device comprising:
A housing having a proximal end carrying said injection button (10) and an opposing distal end;
A rotatable dose setting member (20) connected to the housing for distorting the injection spring when setting the size of the dose to be injected;
An axially movable release element (30) for releasing the strained injection spring for driving the drive and thereby discharging the set dose, the injection button (10) is movable in the axial direction from the first position to the second position, and is movable back from the second position to the first position by the force of the return spring (1). Release element (30),
A plurality of radially movable fingers (31, 15) that releasably connect the injection button (10) and the release element (30), and are provided integrally with the injection button (10). Or fingers (31, 15) provided integrally with the release element (30);
Further comprising
The finger (31) in the first position is in a radial disengagement position where the injection button (10) is disengaged from the release element (30) and the injection button (10 ) In the axial direction independently of the release element (30),
The finger (31) in the second position is in a radially engaged position, wherein the injection button (10) moves axially with the release element (30). A button (10) engages the release element (30);
Spring loaded medical injection device.   2. Set according to claim 1, wherein at least a part of the release element (30) and at least a part of the injection button (10) are guided axially in a channel (21) having an inner diameter. Spring-loaded medical injection device for automatically dispensing doses.   3. The spring loaded medical device for automatically dispensing a set dose according to claim 2, wherein the channel (21) is provided in the dose setting member (20) or in the housing. Injection device.   4. The radial outer edge (16, 32) of the plurality of fingers (15, 31) defines a diameter larger than the inner diameter of the channel (21), according to claim 2 or 3. A spring-loaded medical injection device for automatically discharging a set dose.   5. The spring-loaded type for automatically discharging a set dose according to any one of claims 2 to 4, wherein the plurality of fingers (31) are provided integrally with the release element (30). Medical injection device.   The finger (31) comprises inwardly projecting means (34) that engage at the rear of a ridge (12) provided on the injection button (10) in the engagement position of the finger (31). The spring-loaded medical injection device for automatically discharging a set dose according to claim 5.   The spring-loaded type for automatically discharging a set dose according to any one of claims 2 to 4, wherein the plurality of fingers (15) are provided integrally with the injection button (10). Medical injection device.   The finger (15) is an inwardly projecting means (17) that engages at the rear of a ridge or track (35) provided on the release element (30) at the engagement position of the finger (15). A spring-loaded medical injection device for automatically discharging a set dose according to claim 7.   The set dose according to any one of the preceding claims, wherein the return spring (1) urging the injection button (10) in the distal direction is a polymer spring automatically. Spring-loaded medical injection device.   10. Set according to claim 9, wherein the polymer spring (1) is molded as an integral part of the dose setting member (20) or as an integral part of the injection button (10). Spring-loaded medical injection device for automatically discharging a given dose.

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